1. Field of the Invention
This invention relates to backhoe equipment and, more particularly, to a clamping attachment in the form of a pivotal cantilever for placement on the dipper boom of a backhoe adjacent the backhoe bucket as a replacement for the link plate interconnected to the hydraulic actuator system, the cantilever forming a movable lever arm against which the backhoe bucket can be pivoted so as to clamp an object between the bucket and the clamping device.
2. The Prior Art
The backhoe is a commonly available machine used primarily for digging in the earth. The backhoe derives its name from its method of operation; namely, the action of drawing the digging bucket in a "hoe" action "back" toward the operator. The bucket is pivotally mounted on the end of an articulated boom. Hydraulic actuators supply the necessary forces to position and move the articulated boom and its attached bucket in the desired manner. An operator manipulates various hydraulic controls in order to cause a corresponding hydraulic manipulation of the bucket. A skilled operator finds the backhoe to be a very versatile piece of equipment not only for digging in the earth but also for trenching; breaking walls, concrete, etc.; scooping; and clearing operations.
Numerous attachments have been developed for the backhoe. Examples include chipper attachments; pneumatic hammer attachments, and hydraulically actuated jaws, to name a few. Each of these devices are intended to extend the range of possible applications for the conventional backhoe. However, in most instances the modification of the particular backhoe or rather backhoe bucket for one of these specialty applications renders that particular bucket inoperative as a general purpose digging tool. Continued changeover from one configuration to the other is laborious, time-consuming, and requires that the attachment equipment be readily available at the operating site.
Many operators forego these various pieces of adaptive equipment and simply attempt to use the backhoe for certain tasks for which it is ill-suited. For example, frequently the backhoe is used for lifting a large slab of concrete, a beam, tree trunk, or such other object that is too large to be received in the bucket. This lifting operation is tricky and involves the operator in attempting to clamp the particular, oversize object between the bucket and its supporting boom commonly referred to as the dipper boom. However, since the bucket pivots on the end of the dipper boom, the rearwardly pivoted bucket forms an acute angle with the boom with an ever-decreasing angle. The result is that a fairly thick slab of concrete will tend to slip out of the clamping action as the bucket is pivoted toward the boom. Clearly, the danger associated with slippage of a large slab of concrete is an unacceptable risk necessitating other lifting equipment, costly attachments, or elaborate techniques for handling these types of objects.
In view of the foregoing it would be an advancement in the art to provide a clamping device that cooperates with the existing hydraulic actuator system of a backhoe against which an object can be clamped by a backhoe bucket. It would also be an advancement in the art to provide a clamping device for a backhoe bucket that can be permanently mounted to the backhoe and yet has minimal interference with the conventional operation of the backhoe. It would also be an advancement in the art to provide a clamping apparatus for a backhoe wherein the clamping apparatus can be installed either as new equipment or as a retrofit on existing equipment in the field. Such a novel invention is disclosed and claimed herein.